I need to know a way to remove elements in O(1) time . I used hash table , put the values as keys but there is a problem that the values are not distinct . Is there a way to remove elements in O(1) time if they aren't distinct ?

in this problem. the third test case says that node 2 and node 1 have cats so the path from 1 to 2 has 2 cats which is equal to m . but the jury answer is that there is no path with <= m cats . can anyone help me understand this test case ?

I am participating virtually in ACM Jordan 2017 . the submitting process should be done by sending the file of the code . it the first time that I submit using this way . I am using C# and whatever the problem that I submit for it gives me runtime error . anyone has a solution for this problem ?

I participated in round 446 and gained +73 rating so I became pupil from newbie . when I checked my rating today . it is the same but the color is grey and my title still newbie , also the contests are not in the contests that I participated in . Is anyone facing similar problem ? [UPD] it is fixed now .